A total of five women have accused Franco of sexual misconduct and abuse of power, including four of his former students and an ex girlfriend. Franco has denied the allegations.

He has been criticised for wearing a Time's Up pin to the Golden Globes, where he won Best Actor in a Comedy or Musical for The Disaster Artist.

"How could a person publicly stand by an organisation that helps to provide support for victims of sexual assault while privately preying on people who have no power?" Johansson told a crowd in Los Angeles.

While she didn't refer to Franco by name her representative later confirmed to the Los Angeles Times that she was speaking about the actor.

"I want my pin back, by the way," she said.

Johansson however has been accused of hypocrisy though for singling out Franco and yet having worked in three Woody Allen films, 2005's Match Point, 2006's Scoop and Vicky Cristina Barcelona in 2014.

Scarlett Johannson (L) with director Woody Allen on the set of the 2005 film Match Point. Picture: Supplied

In fact, Johansson told The Guardian in 2014 not to rush to judgement about matters that haven't been stress tested in court.

"It's not like this is somebody that's been prosecuted and found guilty of something, and you can then go, 'I don't support this lifestyle or whatever.' I mean, it's all guesswork," she said. "I don't know anything about it. It would be ridiculous for me to make any kind of assumption one way or the other."

Time's Up has been formed on the back of the #MeToo movement as a way to fund legal defence for people who can't afford it across all industries.

NATALIE PORTMAN: 'I WAS SEXUALLY TERRORISED AT 13'

Natalie Portman has revealed how she experienced "sexual terrorism" when she was 13 after a fan sent her a "rape fantasy" and critics discussed her "budding breasts".

The Oscar-winning actress shared her traumatic experience as she addressed the Los Angeles Women's March.

The 36-year-old told how she turned 12 on the set of her first film Leon: The Professional, where she played a young girl who befriended a hit man in hopes of avenging the murder of her parents.

When the movie was released a year later, she described feeling excited to open her first fan mail but was left horrified when she opened it to find a letter from a man who had written a "rape fantasy" about her.

She went on to tell the crowd: "A countdown was started on my local radio show to my 18th birthday, euphemistically the date that I would be legal to sleep with.

"Movie reviewers talked about my budding breasts in reviews. I understood very quickly, even as a 13-year-old, that if I were to express myself sexually I would feel unsafe and that men would feel entitled to discuss and objectify my body to my great discomfort."

She said from then on she had adjusted her personal and professional behaviour to avoid this happening, and even went as far rejecting roles with kissing scenes.

Portman would try to bolster her "bookish and serious" side and built a reputation as being "prudish, conservative, nerdy and serious".

She said: "At 13 years old, the message from our culture was clear to me. I felt the need to cover my body and to inhibit my expression and my work in order to send my own message to the world that I'm someone worthy of safety and respect.

"The response to my expression, from small comments about my body to more deliberate statements, served to control my behaviour through an environment of sexual terrorism."

FEMALE CELEBRITIES TAKE A STAND

Johansson and Portman were just two celebrities who joined hundreds of thousands of women across the US on the anniversary of Donald Trump's presidency.